This invention relates to a building panel for roofing, siding, walls and the like, adapted to be attached to building structures by concealed fasteners. More particularly, the invention relates to a contoured building panel having locking edge structures and improved nestability for storage and shipment.
The building industry uses sheet and extruded panels for roofing, siding, walls and the like to provide quickly and easily assembled building structures. In the prior art, building panels appear in a variety of configurations and are provided with different types of fastening means for securing the panels to a building structure and for joining adjacent panels at their edges. Use of concealed fasteners has its advantages in that the aesthetic appearance of the assembled building panels may be more pleasing if the fastening screws, clips, nails and the like are not visible. Furthermore, when the panels are exposed to the weather, as on the outside walls of a building, the use of external fasteners is disadvantageous in that the fasteners and any holes in the panel for the fasteners are more likely to be the subject of corrosion and a source for leakage. It is also desirable to provide edge structures which, when joined with edges of adjacent panels, form a liquid-tight joint. U.S. Pat. No. 3,363,380, issued Jan. 16, 1968, discloses a generally wedge-shaped shingle which is secured to a structure by concealed nails. Each shingle has cooperating edge structures with one edge being substantially folded over itself to be adapted to receive the opposite edge structure of an adjacent shingle. Nails secure the shingle by the edge structure which is substantially folded over itself and the nails are concealed from view as they underlie an opposite end portion of the adjacent shingle. A sheathing member is disclosed in U.S. Pat. No. 3,495,363, issued Feb. 17, 1970, having an unexposed fastening means which underlies an end portion of an adjacent sheathing member in an assembled condition. The members are joined at their edge structures by an inwardly hooking surface of one panel received by a cooperating groove on the opposite edge structure of an adjacent panel. Still another form of a contoured building panel having a concealed fastener means, cooperating tongue and groove type end structures and a backing board is disclosed in U.S. Pat. No. 3,886,704, issued June 3, 1975.
A disadvantage of the concealed fastener building panels of the prior art is that they are not easily nestable, if at all, in stacks for shipment and storage. Efficient stacking of such panels is hindered by the configuration of both the contoured body portion and the panel edge structures. In the building industry, the cost of shipment and storage of building panels depends, in part, upon the volume of space occupied which, in turn, is determined by the number of panels that can be stacked per unit volume. Panels that are nestable in a stack reduce such costs by providing more stacked panels per unit volume. One manner of dealing with the nestability problem of stacked panels is shown in U.S. Pat. No. 3,253,376, issued May 31, 1966. There a contoured building panel having a pair of opposed hook-shaped portions at its edges is shown stacked by alternately inverting every other panel in the stack of panels.
The prior art, however, still does not provide a concealed fastener, contoured building panel that can be efficiently nested with other like panels in a vertical stack without alternate stacking. Such a nestable building panel would minimize the shipment and storage costs by permitting vertical stacking of more building panels in a given volume of space.